Pumping device and method for conveying viscous media, in particular adhesives

ABSTRACT

The invention includes a pumping device ( 1, 1   a ) and a method for conveying a viscous medium, in particular adhesives. The pumping device ( 1, 1   a ) has a cylinder unit ( 20 ) as well as a piston unit ( 22 ), which is at least partially contained within the cylinder unit ( 20 ), with the cylinder unit ( 20 ) and the piston unit ( 22 ) together forming a conveying means ( 2 ), which operates according to the reciprocating piston principle. The pumping device ( 1, 1   a ) further has at least one drive shaft ( 7 ) communicating with a motor, via which drive shaft ( 7 ) the cylinder unit ( 20 ) and the piston unit ( 22 ) are rotationally movable about a common axis, and the pumping device ( 1, 1   a ) also has a forced guide being mechanically coupled with the conveying means ( 2 ), by means of which forced guide the rotating movement of the conveying means ( 2 ) is convertible into an alternating forward and return stroke of the piston unit ( 22 ) for the purpose of pumping the respective viscous medium.

CLAIM OF PRIORITY

The present application claim priority to German Application DE 10 2014 224 539.7, filed Dec. 1, 2014, which is incorporate by reference.

FIELD OF THE INVENTION

The present invention relates to a pumping device as well as to a method for conveying highly viscous or viscous media, respectively, in particular adhesives.

BACKGROUND OF THE INVENTION

Devices or methods, respectively, of the type previously mentioned can be used, for instance, in order to convey hot glue from a storage container and provide it for a labeling operation. In this context, devices are known that can be placed upon a container and that supply glue to a glue applicator roll and/or to further means via appropriate pipe connections.

A heatable pump for viscous media is, for instance, known from DE 35 42 848 A1. The pump disclosed there has a piston rod, a pump piston, and also a riser pipe arranged concentrically to the piston rod. A heating element is helically guided around the piston rod. In order to convey glue, a pump piston is moved up and down by means of a linear actuator.

Since such devices require a complex mechanism for generating a linear movement of the pump piston, they are technically elaborate to carry out. In addition, the devices known from the prior art require regular and frequent maintenance in order to prevent a failure of the pump. If hot glue, for instance, is to be provided for a labeling operation by means of such pumps, the pumps have to be replaced in the instance of maintenance or repair, for which the labeling operation has to be interrupted. In particular for a labeling device or for a labeling operation, respectively, pumping devices would therefore be desirable, which are subject to as few signs of wear as possible and which are moreover maintenance-friendly.

SUMMARY OF THE INVENTION

It is therefore the object of the invention to provide both a pumping device and a labeling device with such a pumping device, which are characterized by a simple structure and low-maintenance operation. It is further the object of the present invention to provide a method for conveying viscous medium, which method is simple and which can be carried out with no or minimal complications.

The above objects are solved by a pumping device, a method, and a labeling device, which comprise the features in the independent claims. Further advantageous embodiments of the invention are described in the dependent claims.

The pumping device according to the invention is provided for conveying highly viscous or viscous media, respectively, in particular adhesives. Preferred embodiments of the present invention can be provided, for conveying, for instance, cold glue, in particular casein glue or adhesive solutions, respectively. It is moreover conceivable that hot glue and/or other glues are conveyed by means of the pumping device according to the invention. With regard to the cold glues preferentially to be conveyed, processing temperatures from approximately 15 to 36 degrees Celsius are suitable, where a reasonable viscosity range of approximately 20,000 to 200,000 [mPa·s] can be at a temperature of approximately 20 degrees Celsius.

The pumping device comprises has a cylinder unit as well as a piston unit, which is at least partially contained within the cylinder unit, with the cylinder unit and the piston unit together forming a conveying means, which operates according to the reciprocating piston principle. In this instance, the cylinder unit is mounted on the piston unit. The piston unit is driven rotationally, while the cylinder unit is driven by the piston or set into rotation by the piston, respectively.

The pumping device according to the invention furthermore comprises at least one drive shaft, which is in communication with a motor, via which drive shaft the cylinder unit and the piston unit are rotationally movable about a common axis. The drive shaft can have a vertical orientation during operation of the pumping device. In order to rotatingly drive the drive shaft, the motor can be designed as a gear motor, for instance, and in particular as an electric motor. Other drive variants are also conceivable, for instance, hydraulic drives or the like. In comparison to the linear actuators used in the known pumping devices, such motors require less maintenance effort and have less signs of wear. An appropriate coupling can be arranged between the motor and the drive shaft.

Also provided is a force guide, which is mechanically coupled with the conveying means and by means of which the rotating movement of the conveying means is converted into an alternating forward and return stroke of the cylinder unit for the purpose of pumping the respective viscous medium. Since the piston unit is at least partially contained within the cylinder unit, both the piston unit and the cylinder unit rotate at the same rotational frequency. In particular, the rotational frequencies of the drive shaft and of the conveying means can also be the same. It is moreover conceivable that the force guide guides the conveying means such that the cylinder unit performs both a forward stroke and a return stroke during a complete rotation of the conveying means.

The forward and return stroke of the cylinder unit is in each case carried out by a movement in which the cylinder unit and the piston unit are shifted in relation to each other. In this context, it is conceivable that the relative movement is carried out by an active adjustment of the piston unit, but also that the relative movement is effected by an active adjustment of the cylinder unit.

It is possible here that the piston unit is fixedly in communication with the drive shaft or is directly mechanically coupled to the drive shaft, respectively, as will be described in more detail in the following. In addition, the cylinder unit can be coupled to the force guide or can be in operative connection to the force guide, respectively, and can be shifted relative to the piston unit in the rotating movement of the conveying means. The invention is not limited to such embodiments so that further options are available to the expert for the purpose of effecting a relative movement of a piston unit and a cylinder unit by means of a force guide.

The piston unit can moreover be guided in the cylinder along a direction oriented at least approximately in perpendicular to the rotation axis of the drive shaft. The conveying means can thus have a horizontal orientation or can be arranged in a lying position in a storage container for the adhesive, respectively, during an operation of the pumping device. Thus, the longitudinal axes of the cylinder unit and/or of the piston unit can be oriented in perpendicular to the rotation axis of the drive shaft. An axis along which the forward stroke and the return stroke of the cylinder unit proceed can therefore be oriented in perpendicular to the rotation axis of the drive shaft.

In particularly preferred embodiments, the cylinder unit of the conveying means has one inlet for the highly viscous or viscous medium, respectively, to be conveyed, which inlet is oriented at least approximately in perpendicular to the rotation axis of the drive shaft, or a plurality of inlets for the highly viscous or viscous medium, respectively, to be conveyed, which inlets are oriented at least approximately in perpendicular to the rotation axis of the drive shaft. In this instance, it is possible in conceivable embodiments for the cylinder unit to have exactly one inlet through which a viscous medium or adhesive respectively, enters into the cylinder unit in a return stroke of the piston unit. Due to the return stroke, the viscous medium can then be drawn in by the conveying means. In the rotating movement of the conveying means, the inlet can rotatingly move about the drive shaft.

In further conceivable embodiments, the cylinder unit can have at least two inlets at opposite sides for the highly viscous or viscous medium, respectively, which inlets are each oriented at least approximately in perpendicular to the rotation axis of the drive shaft and are aligned with each other. Provided that the cylinder unit has at least two such inlets, these can rotate together about the drive shaft in the rotating movement of the conveying means. The piston unit can then be preferably completely contained within the cylinder unit and move alternatingly back and forth between the at least two inlets. The alternating movement of the piston unit can furthermore be effected by a mechanical coupling of the cylinder unit to the force guide. The cylinder unit can thus be actively adjusted and thereby effect the forward and return stroke of the piston unit, whereas the piston unit remains fixedly connected to the drive shaft.

In addition, the pumping device can have one or more valves or check valves, respectively. The one or more valves can be designed as ball valves, for instance. In particular, the one or more inlets can each be assigned at least one valve and the one or more outlets of the conveying means can be assigned at least one further valve. In this instance, the valves assigned to the one or more inlets can close in a forward stroke of the piston unit or when compressing the viscous medium, respectively, and open in a return stroke of the piston unit or when drawing in the viscous medium, respectively.

Furthermore, the valves assigned to the one or more outlets can open in a forward stroke of the piston unit or when compressing the viscous medium, respectively, and close in a return stroke of the piston unit or when drawing in the viscous medium, respectively.

As already previously mentioned, it is possible for the drive shaft to be torque-proofly in communication with the piston unit of the conveying means. In particular, such embodiments have proven successful in which the drive shaft at least partially provides a channel for transporting the viscous medium, which channel is in fluidic communication with the piston unit. The drive shaft can supply the viscous medium through the channel to an annular chamber, in which one or more heating means, such as helical heating coils or the like, are arranged for tempering the viscous medium. The helical heating coils can at least partially be guided around the drive shaft. The drive shaft can have a breakthrough through which the viscous medium enters into the annular channel. The annular channel can be formed between a conveyor housing of the pumping device and the drive shaft, with the drive shaft being at least partially contained within the conveyor housing.

The pumping device can further comprise at least one connecting rod unit mechanically coupled to the conveying means, which connecting rod unit is in communication with an eccentrically acting adjustment mechanism. The connecting rod unit can be oriented in parallel to the conveying means with the connecting rod unit maintaining its orientation in parallel to the conveying means continuously throughout a rotating movement of the conveying means.

The eccentrically acting adjustment mechanism can provide a bearing for the connecting rod unit. Taken together the connecting rod unit, the adjustment mechanism and the bearing form a force guide. The eccentrically acting adjustment mechanism itself can, in particular, be designed as an immovable part of the pumping device. In an eccentric adjustment movement of the connecting rod unit, the connecting rod unit can be moved relative to the adjustment mechanism or eccentrically rotate about the adjustment mechanism, respectively. The eccentrically acting adjustment mechanism can be immovably connected to a housing section of the pumping device. Furthermore, the drive shaft can pass through the eccentrically acting adjustment mechanism and, as the case may be, be connected to the conveying means or mechanically coupled with the conveying means, respectively, at its downward facing free end.

The connecting rod unit can, in particular, be designed as a disk, which is in mechanical coupling with the conveying means. A broadside surface of the disk can face toward the conveying means; a further, opposite broadside surface of the disk can be averted from the conveying means. In a conceivable embodiment, the disk or the connecting rod unit, respectively, can be moved rotatingly and preferably at the same rotational frequency as the conveying means via the drive shaft.

In particularly preferred embodiments, there is no direct mechanical connection between the drive shaft and the conveying means. It is possible, for instance, that the connecting rod unit is mechanically coupled with the conveying means and that a rotating movement of the connecting rod unit is transferred from the conveying means via the mechanical coupling to the piston rod unit. By way of the connection of the connecting rod unit to the eccentrically acting adjustment mechanism and of the mechanical coupling of the connecting rod unit to the conveying means, the forward stroke and the return stroke of the piston unit can be effected in the rotating movement of the conveying means and of the connecting rod unit. It is also possible to mechanically couple the connecting rod unit to the drive shaft such that the connecting rod unit is rotatingly moved via the drive shaft. In the rotating movement of the connecting rod unit, the eccentrically acting adjustment mechanism can effect a radial offset of the connecting rod unit and thus a forward stroke and a return stroke of the piston unit.

In this instance it is, in particular, possible that the piston unit and the connecting rod unit are directly mechanically coupled with each other via a bearing journal connection. The bearing journal connection can engage into the connecting rod unit and guide the connecting rod unit along with the conveying means in the rotating movement of the conveying means. The bearing journal connection can have an orientation in parallel with the drive shaft. The bearing journal, the connecting rod unit, and the adjustment mechanism cooperate to form a force guide.

During operation of the pumping device, it is possible that a torque is transmitted via the conveying means or via the rotating cylinder unit, respectively, to the entire pumping device. In order to reduce this torque and to continue to be able to ensure a solid bearing during an operation of the pumping device, it is possible that the pumping device has at least one casing, which is preferably passed around the entire conveying means, and which is immovably mounted and has at least one aperture at its top and/or bottom side. For the immovable bearing, the casing can be, for instance, mechanically fixedly connected to the eccentric adjustment mechanism and/or to a stationary section or component, respectively, of the pumping device. In particularly preferred embodiments, a top side and/or a bottom side of the casing are designed to be completely open. The casing can then be designed as a hollow cylinder, which is opened both at its top side and at its bottom side, which hollow cylinder is passed around the conveying means or contains the conveying means, respectively.

Since the conveying means of the pumping device is embedded in the viscous medium or in the adhesive, respectively, during the operation of the pumping device, the viscous medium or the glue, respectively, can serve as a lubricant for the moved parts of the conveying means. The wear is thus further reduced.

For further reduction of the torque, the pumping device can have one or more webs and/or vanes, which, in particular, extend radially away from the drive shaft. The webs and/or vanes can also be immovably mounted and for this purpose be mechanically connected, as the case may be, to the eccentric adjustment mechanism and/or to a stationary section or component, respectively, of the pumping device.

The present invention moreover comprises a labeling device. The labeling device according to the invention is provided for the application of labels onto objects, such as beverage containers or the like. For this purpose, the labeling device comprises an application unit for adhesive, which application unit is coupled by way of fluidic pipe connections to a pumping device as already previously described. The application unit can be designed, for instance, as a glue roller or the like. The objects can be designed as beverage containers, for instance.

The present invention moreover relates to a method for conveying viscous media. Features as have been previously described regarding the pumping device or the labeling device can also be provided for conceivable embodiments of the method according to the invention. Furthermore, features, which will be described below regarding various embodiments of the method according to the invention, can be present in conceivable embodiments of the pumping device according to the invention or of the labeling device according to the invention, respectively.

The method is suitable for conveying viscous media and, in this context in particular, adhesives or glues, respectively. In the method according to the invention, a cylinder unit and a piston unit, which is at least partially contained within the cylinder unit, form a conveying means for the viscous medium. The conveying means or the cylinder unit and the piston unit, respectively, are rotated about a common axis via a drive shaft. A force guide is mechanically coupled with the conveying means, which force guide, from the rotating movement, transfers an alternating forward and return stroke of the piston unit to the conveying means. In the course of the forward and return stroke, the cylinder unit and the piston unit are moved relative to each other.

In particularly preferred embodiments, the force guide effects at least one forward stroke and at least one return stroke of the piston unit in the course of a complete rotation of the conveying means by 360 degrees.

Furthermore, the drive shaft can be torque-proofly in communication with the piston unit and the cylinder unit can be driven by the piston unit with the rotating movement of the drive shaft. The drive shaft can be directly coupled to the piston unit in this instance.

It is additionally conceivable that the forward and return stroke of the piston unit is effected by way of a connecting rod unit, which is eccentrically moved via an adjustment mechanism and which has a mechanical coupling to the conveying means. The forward stroke and the return stroke can thus result from an eccentric adjustment of the connecting rod unit in the rotating movement of the conveying means.

It is further conceivable that a torque is applied to the connecting rod unit by its mechanical connection to the conveying means, and that as a result thereof the connecting rod unit undergoes an eccentric rotational movement. The connecting rod unit can thus be moved in its rotation at the same rotational frequency as the conveying means and/or as the drive shaft. A torque can thus be transmitted from the drive shaft via the conveying means to the connecting rod unit.

Furthermore, the forward stroke and the return stroke of the piston unit can be effected with the help of a bearing journal or a bearing journal connection, respectively, which mechanically couples the cylinder unit and the connecting rod unit with each other. By way of the bearing journal, a torque can be transmitted from the conveying means to the connecting rod unit.

It is possible, in particular, that the conveying means is rotated about an at least approximately vertically oriented axis. The forward stroke and the return stroke can thus proceed in a horizontal direction or at least approximately in a horizontal direction.

In an appropriate connection, the conveying of the viscous medium can be provided for a labeling operation. It is thus conceivable that the viscous medium is conveyed toward an application unit of a labeling device, and that the viscous medium is applied to the objects via the application unit.

BRIEF DESCRIPTION OF THE FIGURES

In the following passages, the attached figures further illustrate exemplary embodiments of the invention and their advantages. The size ratios of the individual elements in the figures do not necessarily reflect the real size ratios. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged in relation to other elements to facilitate an understanding of the invention.

FIG. 1 shows a schematic and perspective longitudinal cut of an embodiment of a pumping device according to the invention.

FIG. 2 shows a detailed view of a lower section of the exemplary embodiment of a pumping device from FIG. 1.

FIG. 3 shows a further detailed view of a lower section of the exemplary embodiment of a pumping device from FIGS. 1 and 2.

FIG. 4 shows a schematic perspective view of a further embodiment of a pumping device according to the invention.

FIG. 5 shows a detailed view of a lower section of the exemplary embodiment of a pumping device from FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

The same or equivalent elements of the invention are designated by identical reference characters. Furthermore and for the sake of clarity, only the reference characters relevant for describing the respective figure are provided. It should be understood that the detailed description and specific examples of the device and method according to the invention, while indicating preferred embodiments, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

FIG. 1 shows a schematic and perspective longitudinal cut of an embodiment of a pumping device 1 according to the invention. The pumping device 1 has a bearing housing 5, which is designed for a coupling 55 (cf. FIG. 4)—not illustrated in FIG. 1—being contained within it. An electric motor, for instance, or another drive motor, such as, for instance, a mechanical drive connection or an hydraulically operating motor or the like can be placed or flange-mounted, respectively, onto the bearing housing 5, which motor rotatingly drives the drive shaft 7. An exemplary embodiment of an electric motor 50 is illustrated in the embodiment example of FIG. 4, and it can be applied likewise in the same or in a corresponding manner for the embodiment example that is illustrated in the FIGS. 1 to 3.

The pumping device 1 furthermore has a pump cover 3. Prior to putting the pumping device 1 into service, the pump cover 3 is placed onto a storage container for adhesive or for glue, respectively, and seals the storage container toward the top, with the storage container not being illustrated in FIG. 1. The storage container, which is not shown here, can commonly take the form of a pot or a barrel or the like, into the interior of which the pumping device 1 dips into with its length in order to convey the highly viscous medium located therein, in particular the glue or the adhesive, to an outlet nozzle 15, which can be connected with a hose line or with another conveyor line (not illustrated here).

A further part of the pumping device 1 is the conveyor housing 10 and exemplarily illustrated in FIG. 1, which conveyor housing 10 provides an annular channel formed between the drive shaft 7 and the inner cover surface of the conveyor housing 10 for the transport of the viscous or highly viscous medium or adhesive, respectively, and at least partially coaxially encases and contains the drive shaft 7 within it.

The drive shaft 7 is commonly oriented approximately concentrically to the hollow cylindrical conveyor housing 10 and can thus rotate in the conveyor housing 10 in the manner shown. Also discernible is a heating coil, which is helically guided around the drive shaft 7 and thus within the annular channel and which is completely contained within the conveyor housing 10. The heating coil 9 effects a warming, if necessary, of the adhesive being transported along the conveyor housing 10 or along the annular channel toward the top, respectively, or of the highly viscous medium being conveyed therein, respectively.

The conveyor housing 10 or the annular channel, respectively, which is formed between drive shaft 7 and the inner cover surface of the conveyor housing 10, leads toward the top into a pipe nozzle 15 so that the glue or adhesive, respectively, which has been warmed by means of the heating coil 9, is pumped from the annular channel into the pipe nozzle 15. The pipe nozzle 15 is preferentially coupled to a gluing unit or to an application unit for glue, respectively, or to a similar application means (not illustrated here). The pumping device 1 can thus be designed as part of a labeling device and it can supply adhesive in a controllable quantity to an application unit of the labeling device. The pipe nozzle 15 is passed through the pump cover 3 via an aperture 32.

As is discernible in the lower section of the pumping device 1, the drive shaft 7 is fixedly in communication at its downward facing free end with a lying piston unit 22. In this instance, the drive shaft 7 is directly and torque-proofly coupled to the piston unit 22. If the drive shaft 7 is rotatingly moved, the piston unit 22 is thus rotated together with the drive shaft 7. Due to the direct mechanical connection, the drive shaft 7 and the piston unit 22 rotate synchronously.

Also shown is a cylinder unit 20, which, together with the piston unit 22, forms a conveying means 2 for the adhesive, which conveying means 2 operates according to the reciprocating piston principle. The transport or the conveying, respectively, of the adhesive is in this context carried out by a relative movement of the cylinder unit 20 and the piston unit 22 according to the reciprocating piston principle. Due to the arrangement of the piston unit 22 and the associated cylinder unit 20, the direction of both the forward stroke and the return stroke between piston unit 22 and cylinder unit 20 are respectively oriented in perpendicular to the rotation axis of the drive shaft 7.

At the same time, the piston unit 22 supplies a linear guide for the cylinder unit 20 such that the cylinder unit 20 can perform both its forward stroke and its return stroke in a linear direction. There is no direct mechanical coupling between the drive shaft 7 and the cylinder unit 20. For the rotating movement of the cylinder unit 20, the cylinder unit 20 is thus driven by the piston unit 22 and in this connection a torque is applied to the cylinder unit 20 via the piston unit 22.

In order to effect the adhesive to be drawn in and conveyed with the forward stroke and return stroke of the cylinder unit 20, two ball valves 24 and 26 are provided in the present instance. Here, the two ball valves 24 and 26 operate such that the valve 24, which is positioned in the area of the inlet 23, opens with a return stroke of the piston unit 22 and of the cylinder unit 20 so that adhesive is drawn into the cylinder unit 20 through the inlet 23. At the same time, the valve 26 closes so that a negative pressure for drawing in the adhesive builds in the cylinder unit 20. The inlet 23 for the adhesive is placed into the cylinder unit 20 in perpendicular to the rotation axis of the drive shaft 7. The valve 24, which is arranged in the area of the inlet 23, vice versa closes with a return stroke of the piston unit 20, whereas the other valve 26 opens.

The drive shaft 7 has a channel 36, which is in fluidic communication with the conveying means 2, or which leads into the conveying means 2, respectively. Since the adhesive, which was drawn in through the inlet 33 by means of the return stroke of the piston unit 20 and which is in the interior of the cylinder unit 20, is compressed, and since thus a positive pressure builds in the conveying means 2, a transport of the adhesive is carried out from the conveying means 2 into the channel 36 of the drive shaft 7.

The channel 36 has a breakthrough 41, through which the adhesive is passed into the annular space of the conveyor housing 10. As already previously described, the adhesive is then transported or pumped, respectively, from the annular space or from the conveyor housing 10, respectively, into the pipe nozzle 15.

In the position shown in FIG. 1, the cylinder unit 20 has already performed a return stroke so that adhesive is now contained within the conveying means 2 and the inlet 23 is closed by the ball valve 24. Further discernible is a connecting rod unit 19, which is mechanically coupled to the cylinder unit 20 via a bearing journal 17.

The connecting rod unit 19 is in communication with an eccentrically acting adjustment means 30 and is vertically immovably mounted through the adjustment means 30. By way of the mechanical connection of the conveying means 2 via the bearing journal 17 to the connecting rod unit 19, the connecting rod unit 19 is guided together with the conveying means 2 in a rotating movement, and a torque is applied to the connecting rod unit 19 by the conveying means 2. The connecting rod unit 19 is eccentrically offset in its rotating movement via the adjustment means 30 and in this connection guides along the cylinder unit 20 of the conveying means 2. The associated radial offset of the bearing journal 17 relative to the rotation axis of the drive shaft 7 effects an adjustment of the cylinder unit 20 in a radial direction and thus both the forward stroke and the return stroke of the piston unit 22. Together, the bearing journal 17, connecting rod unit 19, and the adjustment mechanism 30 form a force guide 38.

From FIG. 1 it is here discernible that both the forward stroke and the return stroke of the piston unit 22 are effected by an adjustment of the cylinder unit 20, which adjustment is radial relative to the rotation axis of the drive shaft 7, while the piston unit 22 is torque-proofly connected to the drive shaft 7 and undergoes no radial offset.

The connecting rod unit 19 is moreover formed as a disk and in its rotary movement it rotates relative to the adjustment mechanism 30, which is immovably and fixedly connected with the conveyor housing 10.

A further part of the pumping device 1 is a casing 33, within which the conveying means 2 is contained and which is designed as a hollow cylinder and open both at its top side and at its bottom side. As a result, adhesive can pass through the casing 33 and become contained within and transported by the conveying means 2. Since the rotating movement of the conveying means 2 is carried out with eccentric offset of the cylinder unit 20 under contact with adhesive, a torque is applied upon the entire pumping device 1 during an operation. The torque acting on the pumping device 1 can advantageously be reduced or supported, respectively, by means of the casing 33. In this instance, the casing 33 is designed as an immovable sleeve 34 and is fixedly in communication with a stationary component or a stationary section of the pumping device 1, respectively.

As an alternative or in addition to the casing 33 or to the sleeve 34, respectively, the pumping device 1 can have one or more webs and/or vanes designed as stationary parts of the pumping device 1 and radially projecting from the drive shaft 7, which webs and/or vanes reduce the torque acting on the pumping device 1. For the purpose of clarity, the webs or vanes, respectively, are not illustrated in the figures of the present patent application.

FIG. 2 shows a detailed view of a lower section of the exemplary embodiment of a pumping device 1 from FIG. 1. Here, the direct and torque-proof connection between the drive shaft 7 and the piston unit 22 is once more clearly discernible. In the rotating movement of the drive shaft 7, the drive shaft 7 and the piston unit 22 rotate at the same rotational frequency.

From the schematic and perspective longitudinal cut of FIG. 2, it is also once more clearly discernible that neither the connecting rod unit 19 nor the cylinder unit 20 are in direct mechanical communication with the drive shaft 7. A torque is thus transmitted from the drive shaft 7 to the piston unit 22, with the cylinder unit 20 being driven by the piston unit 22 in its rotating movement. By means of the bearing journal connection or the bearing journal 17, respectively, a torque is applied to the connecting rod unit 19 by the conveying means 2 or by the cylinder unit 20, respectively, so that the conveying means 2 and the connecting rod unit 19 rotate at the same rotational frequency.

As already previously mentioned, the adjustment device 30 effects a radial offset of the connecting rod unit 19, of the bearing journal 17, and of the cylinder unit 20 during their rotating movement. In this instance, the connecting rod unit 19, the bearing journal 17, and the cylinder unit 20 rotate relative to the adjustment mechanism 30, with the adjustment mechanism 30 being fixedly connected to the immovable conveyor housing 10 of the pumping device 1. Since the piston unit 22 is fixedly coupled to the drive shaft 7, both the forward stroke and the return stroke of the piston unit 22 in the cylinder unit 20 are effected by the radial offset of the cylinder unit 20 in the rotating movement of the conveying means 2.

FIG. 3 shows a further detailed view of a lower section of the exemplary embodiment of a pumping device 1 from FIGS. 1 and 2. The inlet 23 of the cylinder unit 20 is illustrated once more, which inlet 23 can be opened or closed in operative connection with the ball valve 24. In the present illustration, the bearing journal 17 is designed as a one-piece part of the cylinder unit 20, in further conceivable embodiments; however, it can also be designed as a separate component or as a one-piece part of the connecting rod unit 19.

FIG. 3 in addition once more shows a fixed connection between the casing 33 or the sleeve 34, respectively, and the eccentrically acting adjustment mechanism 30. Since the eccentrically acting adjustment mechanism 30 is in communication with the stationary conveyor housing 10, the eccentrically acting adjustment mechanism 30 as well as the casing 33 or the sleeve 34, respectively are designed as immovable part of the pumping device 1. Moreover, the conveyor housing 10 rests on the adjustment mechanism 30, with the adjustment mechanism 30 partially dipping into the conveyor housing 10.

FIG. 4 shows a schematic perspective view of a further embodiment of a pumping device 1 a according to the invention. The pumping device 1 a according to the exemplary embodiment of the FIGS. 4 and 5 has one inlet 23 and one inlet 25, respectively, for adhesive on opposite sides of the cylinder unit 20, with the inlets 23 and 25 being aligned with each other in perpendicular to the rotation axis of the drive shaft 7.

The further components of the pumping device 1 a, which are not designed as part of the conveying means 2, have an identical structure according to the pumping device 1 from the previous exemplary embodiment of FIGS. 1 to 3 so that the individual components will not be repeatedly referred to.

The piston unit 22, which is completely contained within the cylinder unit 20 in the exemplary embodiment of the FIGS. 4 and 5, is moved back and forth between the two inlets 23 and 25 in the rotating movement of the conveying means 2. For this purpose, the bearing journal 17, which is designed as an integral part of the cylinder unit 20, engages into the connecting rod unit 19. In the rotating movement of the cylinder unit 20, the connecting rod unit 19 is rotatingly moved along with the conveying means 2, and due to the mechanical connection between the connecting rod unit 19 and the cylinder unit 20 via the bearing journal 17, the connecting rod 19 effects a radial offset of the cylinder unit 20 in the rotating movement of the conveying means 2.

The first ball valve 24 is assigned to the first inlet 23, while the second ball valve 24′ is assigned to the second inlet 25. In the course of a complete rotation of the conveying means 2, the ball valves 24 and 24′ are opened and closed alternatingly such that adhesive is drawn in either via the first inlet 23 or via the second inlet 25 in dependence on the respective position of the piston unit 22. In one portion of the cylinder unit 20, a compression of adhesive is continuously carried out over the course of time, whereas in a further portion and according to the position or the movement direction of the piston unit 22, respectively, a drawing in of adhesive via the inlet 23 or 25 is carried out.

High throughput rates of adhesive can be conveyed per time unit by means of the embodiments according to the example of the FIGS. 4 and 5, and at the same time, the pumping device 1 a can moreover be operated in a low-wear manner.

FIG. 5 shows a detailed view of a lower section of the exemplary embodiment of a pumping device 1 a from FIG. 4. Illustrated once more are the ball valves 26 and 26′ already shown in FIG. 4. In dependence on the relative position of the piston unit 22 in the cylinder unit 20 or in dependence on the rotary position of the conveying means 2, respectively, one of the two ball valves 26 or 26′ is always opened, whereas the other of the two ball valves 26 or 26′, respectively, is closed. In the exemplary embodiment according to the FIGS. 4 and 5, the piston unit 22 is again in fluidic communication with the channel 36 of the drive shaft 7. Under compression of the adhesive or of the glue, respectively, in the conveying means 2, the adhesive or glue, respectively, can pass through the opened ball valve 26 or 26′, respectively, and enter from the piston unit 22 into the channel 36 of the drive shaft 7. From the channel 36 and via the breakthrough 41, the adhesive or glue, respectively, then reaches the annular space of the conveyor housing 10, where it is tempered and then supplied toward a downstream application unit of the labeling device via the pipe nozzle 15 (cf. FIG. 4).

The invention has been described with reference to a preferred embodiment. Those skilled in the art will appreciate that numerous changes and modifications can be made to the preferred embodiments of the invention and that such changes and modifications can be made without departing from the spirit of the invention. It is, therefore, intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the invention.

LIST OF REFERENCE CHARACTERS

-   -   1 Pumping device     -   2 Conveying means     -   3 Pump cover     -   5 Bearing housing     -   7 Drive shaft     -   9 Heating coil     -   10 Conveyor housing     -   15 Pipe nozzle     -   17 Bearing journal     -   19 Connecting rod unit     -   20 Cylinder unit     -   21 Breakthrough     -   22 Piston unit     -   23 Inlet     -   24 Ball valve     -   25 Inlet     -   26 Ball valve     -   30 Adjustment mechanism     -   32 Aperture     -   33 Casing     -   34 Sleeve     -   36 Channel     -   38 Force guide     -   41 Breakthrough     -   50 Electric motor     -   55 Coupling 

1. A pumping device (1, 1 a) for conveying a viscous medium, the pumping device comprising a cylinder unit (20) and a piston unit (22), which is at least partially contained within the cylinder unit (20), wherein the cylinder unit (20) and the piston unit (22) together form a conveying means (2), which operates according to the reciprocating piston principle; at least one drive shaft (7) being in communication with a motor (50), wherein the cylinder unit (20) and the piston unit (22) are rotationally movable about a common axis via the drive shaft (7); and force guide (38) being mechanically coupled to the conveying means (2), which force guide (38) converts the rotating movement of the conveying means (2) into an alternating forward and return stroke of the piston unit (22) for the purpose of pumping a viscous medium, wherein the piston unit (22) and at least one connecting rod unit (19) are directly mechanically coupled with each other via a bearing journal connection (17), and wherein the forward and return strokes of the piston unit (22) are effectable via the connecting rod unit (19), which is eccentrically movable via an adjustment mechanism (30) and which has a mechanical coupling to the conveying means (2).
 2. The pumping device of claim 1, in which the piston unit (22) is guided in the cylinder unit (20) along a direction oriented approximately perpendicular to the rotation axis of the drive shaft (7).
 3. The pumping device of claim 2, in which the cylinder unit (20) of the conveying means (2) has one or more inlets (23, 25) for the viscous medium, which inlets (23, 25) are oriented approximately perpendicular to the rotation axis of the drive shaft (7).
 4. The pumping device of claim 3, in which the drive shaft (7) is torque-proofly in communication with the piston unit (22) of the conveying means (2).
 5. The pumping device of claim 4, in which the drive shaft (7) at least partially provides a channel (36) for transporting the viscous medium, which channel (36) is in fluidic communication with the piston unit (22).
 6. The pumping device of claim 5, in which the at least one connecting rod unit (19), is in communication with an eccentrically acting adjustment mechanism (30) for the purpose of the forward and return stroke of the piston unit (22).
 7. The pumping device of claim 6, further comprising at least one casing (33) which is immovably mounted to a conveyor housing (10) and has at least one aperture on its top and/or bottom side.
 8. (canceled)
 9. A method for conveying a viscous medium, comprising: rotating a cylinder unit (20) and a piston unit (22), which together form a conveying means (2), where the piston unit (22) is at least partially contained within the cylinder unit (20), about a common axis via a drive shaft (7), wherein a force guide (38) is mechanically coupled with the conveying means (2), which force guide (38), from the rotating movement, transfers an alternating forward and return stroke of the piston unit (22) to the conveying means (2).
 10. The method of claim 9, in which the force guide (38) effects at least one forward stroke and at least one return stroke of the piston unit (22) in the course of a complete rotation of the conveying means (2) by 360 degrees.
 11. The method of claim 10, in which the drive shaft (7) is torque-proofly in communication with the piston unit (22) and the cylinder unit (20) is driven by the piston unit (22) with the rotating movement of the drive shaft (7).
 12. The method of claim 11, in which the forward and return stroke of the piston unit (22) is effected via a connecting rod unit (19), which is eccentrically moved via an adjustment mechanism (30) and which has a mechanical coupling to the conveying means (2).
 13. The method of claim 12, in which the forward stroke and the return stroke of the piston unit (22) are effected with the help of a bearing journal connection (17), which mechanically couples the cylinder unit (20) and the connecting rod unit (19) with each other.
 14. The method of claim 13, in which the conveying means (2) is rotated about an at least approximately vertically oriented axis.
 15. The method of claim 14, in which the viscous medium is conveyed toward an application unit of a labeling device and the viscous medium is applied to objects via the application unit.
 16. The pumping device of claim 7, wherein the at least one casing (33) surrounds the entire conveying means (2).
 17. The pumping device of claim 16 further comprising at least one application unit for adhesive, which application unit is coupled via fluidic pipe connections to the conveyor housing (10). 